This invention relates to the field of image processing technology by which the image data supplied from an image data source such as a film scanner is subjected to specified image processing schemes so as to produce output image data to be supplied to a printer or other output device.
Heretofore, the images recorded on photographic films such as negatives and reversals (which are hereunder referred to simply as xe2x80x9cfilmsxe2x80x9d) have been commonly printed on light-sensitive materials (photographic paper) by means of direct exposure in which the film image is projected onto the light-sensitive material to achieve its areal exposure.
A new technology has recently been introduced and this is a printer that relies upon digital exposure. Briefly, the image recorded on a film is read photoelectrically, converted to digital signals and subjected to various image processing operations to produce image data for recording purposes; recording light that has been modulated in accordance with the image data is used to scan and expose a light-sensitive material to record a latent image, which is subsequently developed to produce a finished print. The printer operating on this principle has been commercialized as a digital photoprinter.
In the digital photoprinter, images can be processed as digital image data to determine the exposing conditions for printing and, hence, not only the assembling of images and the splitting of a single image into plural images but also the compositing of characters can be performed by processing the image data; as a result, prints can be outputted after various editing and/or processing operations have been performed in accordance with specific uses. Outputting images as prints (photographs) is not the sole capability of the digital photoprinter; the image data can be supplied into a computer or the like and stored in recording media such as a floppy disk; hence, the image data can be put to various non-photographic uses.
Having these features, the digital photoprinter is basically composed of the following three parts: a scanner (image reading apparatus) that reads the image on a film photoelectrically; an image processing apparatus (setup apparatus) that processes the captured image and determines the exposing conditions for image recording; and a printer (image recording apparatus) that scan exposes a light-sensitive material in accordance with the determined exposing conditions and performs development and other necessary processing on the exposed light-sensitive material to produce a print.
In the scanner, reading light issuing from a light source is allowed to be incident on a film, from which projected light bearing the image recorded on the film is produced and focused by an imaging lens to form a sharp image on an image sensor such as a CCD sensor; the image is then captured by photoelectric conversion and, after being optionally subjected to various image processing steps, sent to the image processing apparatus as data for the image on the film (as image data signals).
In the image processing apparatus, image processing conditions are set on the basis of the image data captured with the scanner and image processing as determined by the thus set conditions is performed on the captured image data and the resulting output image data for image recording (i.e., exposing conditions) are sent to the printer.
In the printer, if it is of a type that relies upon exposure by scanning with an optical beam, the latter is modulated in accordance with the image data sent from the image processing apparatus and deflected in a main scanning direction as the light-sensitive material is transported in an auxiliary scanning direction perpendicular to the main scanning direction, whereby a latent image is formed as the result of exposure (printing) of the light-sensitive material with the image bearing optical beam. Subsequently, development and other processing as determined by the light-sensitive material are performed to produce a print (photograph) reproducing the image that was recorded on the film.
As already mentioned, one big feature of the digital photoprinter is that images can be processed as digital image (i.e., digital processing of image data is possible) to determine the exposing conditions for printing; therefore, by means of the digital photoprinter, various image processing operations steps that have been impossible or difficult to achieve by the conventional direct exposure technique, as exemplified by the correction of washed-out highlights or flat shadows due to the taking of pictures with backlight or an electronic flash, the correction of under- or over-exposure, compensation for the insufficiency of marginal lumination, sharpening and the compression/extension of the density""s dynamic range (imparting a dodging effect by image processing), can be performed with great latitude or flexibility to produce prints of very high quality.
In addition, according to digital image processing, the above-mentioned image adjusting (correcting) steps are applied not only to the whole image; if desired, any region of the image, for example, its subject, can be selected and the above-mentioned flexible image adjustments can be performed on the selected area.
An object, therefore, of the present invention is to provide an improved digital image processing method that is suitable for use with a digital photoprinter which receives image data from an image data source and which performs specified image processing on the received image data to produce output image data.
A particular object of the invention is to provide an image processing method by which specified image processing can be performed on selected specific regions of the images in a plurality of related frames by a simple procedure and with high efficiency so that high-quality prints that effectively satisfy a customer""s request and other needs can be output with high productivity.
The stated object of the invention can be attained by an image processing method for processing images in a plurality of related frames, in which the image data supplied from an image data source is subjected to specified image processing so as to produce output image data, comprising the steps of: in the processing of an image in a first frame among the plurality of related frames, designating a specific region in the first frame; calculating an image characteristic quantity of the specific region; and subjecting the specific region to image modification; storing information about the image characteristic quantity of the specific region and the image modification of specific region; and, further comprising the steps of: in the processing of the images in second and subsequent frames, extracting a similar region that is similar in said image characteristic quantity to the specific region without the image modification in said first frame; and subjecting the similar region to the same image modification as has been performed on the specific region of said first frame.
Preferably, said specific region is at least one member of the group consisting of a human subject taken as a whole, his or her face, hair on the head, eyes, lips, trunk, clothing and accessories.
In another preferred embodiment, said image characteristic quantity is at least one member of the group consisting of position and shape characteristics, density characteristics, color tint characteristics, texture characteristics and space frequency characteristics.
In yet another preferred embodiment, the image characteristic quantity of the specific region before the image modification of said first frame is stored and later used as a criterion for determining as to whether similar regions extracted from the second and subsequent frames need be corrected or not.
The invention further provides an image processing method for processing images in a plurality of related frames and for subjecting image data of the respective images in the plurality of the related frames supplied from an image data source to specific image processing so as to produce output image data of the respective images, comprising:
a step of processing an image in a first frame among the plurality of the related frames, comprising steps of designating manually a specific region having a specific image in the first frame, calculating an image characteristic quantity of the specific image in the specific region and then modifying manually the specific image in the specific region as well as storing information about the image characteristic quantity of the specific region and what was modified about the specific image; and
a step of processing of the images in second and subsequent frames, comprising the steps of extracting automatically a similar region that is similar in said image characteristic quantity to the specific region of unmodified specific image in said first frame and subjecting automatically an image in the similar region to the same image modification as has been performed on the specific image in the specific region of the first frame.